1. Field of the Invention
The present invention relates generally to the fields of interventional radiology and medical devices. More specifically, the present invention relates to a novel adjustable sideholes catheter for use in treating, inter alia, venous or arterial thrombus by regulating both the injection site and volume of drug injected.
2. Description of the Related Art
Catheters are being used increasingly as a means for delivering diagnostic or therapeutic agents to internal target sites that can be accessed through the circulatory system. For example, in angiography, catheters are designed to deliver a radio-opaque agent to a target site within a blood vessel, to allow radiographic viewing of the vessel and of the blood flow characteristics near the release site. For the treatment of localized disease, such as solid tumors, catheters allow a therapeutic agent to be delivered to the target site at a relatively high concentration with minimal side effects.
U.S. Pat. No. 4,739,768 describes a catheter having a guide wire. The catheter may be guided from an external body access site such as through the femoral artery, to an internal tissue site. The catheter progresses through a tortuous path of at least about 5 cm through vessels of less than about 3 mm inner diameter.
Catheters with multiple tiny sideholes over a length of 5 to 15 cm on the distal end of catheter have been used in thrombolytic therapy for many years. The lower rate of infusion (1-2 ml/minute) of thrombolytic drugs was widely employed in routing procedures. However, thrombolytic drugs only pass through a few proximal sideholes when this lower rate of infusion (1-2 ml/minute) was used. Consequently, most drugs are diverted into the blood circulation and never reach the target thrombus. This effect found with prior art catheters has resulted in a devaluation of local thrombolytic therapy, especially when such a technique is indicated for venous thrombolytic therapy. Thus, high doses of drugs become diluted entering the blood flow and pass through systemic circulation. This is, therefore, one of factors that make venous catheter-directed thrombolytic therapy longer than local arterial thrombolytic therapy. No prior art methods or catheters to avoid this phenomenon have been reported.
The prior art is deficient in the lack of effective means of treating, inter alia, venous or arterial thrombus with a controllable injection site and volume. The present invention fulfills this longstanding need and desire in the art.